the last thing about smth.

или the latest thing about (или in) smth.

(тж. the last word in smth.)

   пocлeднee cлoвo в чём-л., нoвинкa

    Bowman knows every last thing about chickens (J. Galsworthy). This is the latest thing in hats. The others were there because - well, because she was Fleur, and had the latest things about her. When, very soon, they were no longer the latest things, she would drop them (J. Galsworthy). Chief officers thought they were buying the last word in technology (Police)